package com.cscp.javastudy.juc.forkjoin;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.stream.LongStream;

public class ForkJoinDemoTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
//        test1();//8048
//        test2();//7988
        test3();//394

    }

    /**
     * 普通写法
     */
    public static void test1(){
        Long sum = 0L;
        long start = System.currentTimeMillis();
        for (Long i = 1L; i <10_0000_0000; i++) {
            sum += i;
        }
        long end = System.currentTimeMillis();
        System.out.println("sum="+"时间："+(end-start));
    }

    /**
     * forkJoin处理
     * @throws ExecutionException
     * @throws InterruptedException
     */
    public static void test2() throws ExecutionException, InterruptedException {
        long start = System.currentTimeMillis();
        ForkJoinPool forkJoinPool = new ForkJoinPool();
        ForkJoinTask<Long> task = new ForkJoinDemo(0L, 10_0000_0000L);
        ForkJoinTask<Long> submit = forkJoinPool.submit(task);
        Long sum = submit.get();//会阻塞
        long end = System.currentTimeMillis();
        System.out.println("sum="+"时间："+(end-start));
    }

    public static void test3(){
        long start = System.currentTimeMillis();
        //Stream并行流
        LongStream.rangeClosed(0L,10_0000_0000L).parallel().reduce(0,Long::sum);
        long end = System.currentTimeMillis();
        System.out.println("sum="+"时间："+(end-start));
    }
}
